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* bootup: move 'usermodehelper_enable()' a little earlierwangyanqing2011-09-29
| | | | | | | | | | | | | | | | | | | | | | | | Commit d5767c53535a ("bootup: move 'usermodehelper_enable()' to the end of do_basic_setup()") moved 'usermodehelper_enable()' to end of do_basic_setup() to after the initcalls. But then I get failed to let uvesafb work on my computer, and lose the splash boot. So maybe we could start usermodehelper_enable a little early to make some task work that need eary init with the help of user mode. [ I would *really* prefer that initcalls not call into user space - even the real 'init' hasn't been execve'd yet, after all! But for uvesafb it really does look like we don't have much choice. I considered doing this when we mount the root filesystem, but depending on config options that is in multiple places. We could do the usermode helper enable as a rootfs_initcall().. So I'm just using wang yanqing's trivial patch. It's not wonderful, but it's simple and should work. We should revisit this some day, though. - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bootup: move 'usermodehelper_enable()' to the end of do_basic_setup()Linus Torvalds2011-09-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Doing it just before starting to call into cpu_idle() made a sick kind of sense only because the original bug we fixed (see commit 288d5abec831: "Boot up with usermodehelper disabled") was about problems with some scheduler data structures not being initialized, and they had better be initialized at that point. But it really didn't make any other conceptual sense, and doing it after the initial "schedule()" call for the idle thread actually opened up a race: what if the main initialization thread did everything without needing to sleep, and got all the way into user land too? Without actually having scheduled back to the idle thread? Now, in normal circumstances that doesn't ever happen, but it looks like Richard Cochran triggered exactly that on his ARM IXP4xx machines: "I have some ARM IXP4xx based machines that use the two on chip MAC ports (aka NPEs). The NPE needs a firmware in order to function. Ever since the following commit [that 288d5abec831 one], it is no longer possible to bring up the interfaces during the init scripts." with a call trace showing an ioctl coming from user space. Richard says: "The init is busybox, and the startup script does mount, syslogd, and then ifup, so that all can go by quickly." The fix is to move the usermodehelper_enable() into the main 'init' thread, and just put it after we've done all our initcalls. By then, everything really should be up, but we've obviously not actually started the user-mode portion of init yet. Reported-and-tested-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* init: carefully handle loglevel option on kernel cmdline.Alexander Sverdlin2011-09-21
| | | | | | | | | | | | | | | When a malformed loglevel value (for example "${abc}") is passed on the kernel cmdline, the loglevel itself is being set to 0. That then suppresses all following messages, including all the errors and crashes caused by other malformed cmdline options. This could make debugging process quite tricky. This patch leaves the previous value of loglevel if the new value is incorrect and reports an error code in this case. Signed-off-by: Alexander Sverdlin <alexander.sverdlin@sysgo.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Boot up with usermodehelper disabledLinus Torvalds2011-08-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The core device layer sends tons of uevent notifications for each device it finds, and if the kernel has been built with a non-empty CONFIG_UEVENT_HELPER_PATH that will make us try to execute the usermode helper binary for all these events very early in the boot. Not only won't the root filesystem even be mounted at that point, we literally won't have necessarily even initialized all the process handling data structures at that point, which causes no end of silly problems even when the usermode helper doesn't actually succeed in executing. So just use our existing infrastructure to disable the usermodehelpers to make the kernel start out with them disabled. We enable them when we've at least initialized stuff a bit. Problems related to an uninitialized init_ipc_ns.ids[IPC_SHM_IDS].rw_mutex reported by various people. Reported-by: Manuel Lauss <manuel.lauss@googlemail.com> Reported-by: Richard Weinberger <richard@nod.at> Reported-by: Marc Zyngier <maz@misterjones.org> Acked-by: Kay Sievers <kay.sievers@vrfy.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tmpfs: miscellaneous trivial cleanupsHugh Dickins2011-08-03
| | | | | | | | | | | | | | While it's at its least, make a number of boring nitpicky cleanups to shmem.c, mostly for consistency of variable naming. Things like "swap" instead of "entry", "pgoff_t index" instead of "unsigned long idx". And since everything else here is prefixed "shmem_", better change init_tmpfs() to shmem_init(). Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* init: skip calibration delay if previously doneSameer Nanda2011-07-25
| | | | | | | | | | | | | | | | | | | For each CPU, do the calibration delay only once. For subsequent calls, use the cached per-CPU value of loops_per_jiffy. This saves about 200ms of resume time on dual core Intel Atom N5xx based systems. This helps bring down the kernel resume time on such systems from about 500ms to about 300ms. [akpm@linux-foundation.org: make cpu_loops_per_jiffy static] [akpm@linux-foundation.org: clean up message text] [akpm@linux-foundation.org: fix things up after upstream rmk changes] Signed-off-by: Sameer Nanda <snanda@chromium.org> Cc: Phil Carmody <ext-phil.2.carmody@nokia.com> Cc: Andrew Worsley <amworsley@gmail.com> Cc: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: remove the leftovers of noswapaccountWANG Cong2011-07-25
| | | | | | | | | | | In commit a2c8990aed5ab ("memsw: remove noswapaccount kernel parameter"), Michal forgot to remove some left pieces of noswapaccount in the tree, this patch removes them all. Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
*-----. Merge branches 'x86-urgent-for-linus', 'core-debug-for-linus', ↵Linus Torvalds2011-07-23
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'irq-core-for-linus' and 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: um: Make rwsem.S depend on CONFIG_RWSEM_XCHGADD_ALGORITHM * 'core-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: debug: Make CONFIG_EXPERT select CONFIG_DEBUG_KERNEL to unhide debug options * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Remove unused CHECK_IRQ_PER_CPU() * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf tools, x86: Fix 32-bit compile on 64-bit system
| | * | | debug: Make CONFIG_EXPERT select CONFIG_DEBUG_KERNEL to unhide debug optionsJosh Triplett2011-06-06
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Several debugging options currently default to y, such as CONFIG_DEBUG_BUGVERBOSE and CONFIG_DEBUG_RODATA. Embedded users might want to turn those options off to save space; however, turning them off requires turning on CONFIG_DEBUG_KERNEL to unhide them. Since CONFIG_DEBUG_KERNEL exists specifically to unhide debugging options, and CONFIG_EXPERT exists specifically to unhide options potentially needed by experts and/or embedded users, make CONFIG_EXPERT automatically imply CONFIG_DEBUG_KERNEL. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20110606012358.GA1909@leaf Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | Merge branch 'timers-cleanup-for-linus' of ↵Linus Torvalds2011-07-22
|\ \ \ \ | |_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-cleanup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: mips: Fix i8253 clockevent fallout i8253: Cleanup outb/inb magic arm: Footbridge: Use common i8253 clockevent mips: Use common i8253 clockevent x86: Use common i8253 clockevent i8253: Create common clockevent implementation i8253: Export i8253_lock unconditionally pcpskr: MIPS: Make config dependencies finer grained pcspkr: Cleanup Kconfig dependencies i8253: Move remaining content and delete asm/i8253.h i8253: Consolidate definitions of PIT_LATCH x86: i8253: Consolidate definitions of global_clock_event i8253: Alpha, PowerPC: Remove unused asm/8253pit.h alpha: i8253: Cleanup remaining users of i8253pit.h i8253: Remove I8253_LOCK config i8253: Make pcsp sound driver use the shared i8253_lock i8253: Make pcspkr input driver use the shared i8253_lock i8253: Consolidate all kernel definitions of i8253_lock i8253: Unify all kernel declarations of i8253_lock i8253: Create linux/i8253.h and use it in all 8253 related files
| * | | pcspkr: Cleanup Kconfig dependenciesRalf Baechle2011-06-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lenghty lists of the kind "depends on ARCH1 || ARCH2 ... || ARCH123" are usually either wrong or too coarse grained. Or plain an ugly sin. [ tglx: Fixed up amigaone ] Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: linux-alpha@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Gerhard Pircher <gerhard_pircher@gmx.net> Link: http://lkml.kernel.org/r/20110601180610.984881988@duck.linux-mips.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | i8253: Consolidate all kernel definitions of i8253_lockRalf Baechle2011-06-09
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move them to drivers/clocksource/i8253.c and remove the implementations in arch/ [ tglx: Avoid the extra file in lib - folded arch patches in. The export will become conditional in a later step ] Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Link: http://lkml.kernel.org/r/20110601180610.221426078@duck.linux-mips.net Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | / Fix CPU spinlock lockups on secondary CPU bringupRussell King2011-06-23
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Secondary CPU bringup typically calls calibrate_delay() during its initialization. However, calibrate_delay() modifies a global variable (loops_per_jiffy) used for udelay() and __delay(). A side effect of 71c696b1 ("calibrate: extract fall-back calculation into own helper") introduced in the 2.6.39 merge window means that we end up with a substantial period where loops_per_jiffy is zero. This causes the spinlock debugging code to malfunction: u64 loops = loops_per_jiffy * HZ; for (;;) { for (i = 0; i < loops; i++) { if (arch_spin_trylock(&lock->raw_lock)) return; __delay(1); } ... } by never calling arch_spin_trylock() - resulting in the CPU locking up in an infinite loop inside __spin_lock_debug(). Work around this by only writing to loops_per_jiffy only once we have completed all the calibration decisions. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Cc: <stable@kernel.org> (2.6.39-stable) -- Better solutions (such as omitting the calibration for secondary CPUs, or arranging for calibrate_delay() to return the LPJ value and leave it to the caller to decide where to store it) are a possibility, but would be much more invasive into each architecture. I think this is the best solution for -rc and stable, but it should be revisited for the next merge window. init/calibrate.c | 14 ++++++++------ 1 files changed, 8 insertions(+), 6 deletions(-) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | generic-ipi: Fix kexec boot crash by initializing call_single_queue before ↵Takao Indoh2011-06-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | enabling interrupts There is a problem that kdump(2nd kernel) sometimes hangs up due to a pending IPI from 1st kernel. Kernel panic occurs because IPI comes before call_single_queue is initialized. To fix the crash, rename init_call_single_data() to call_function_init() and call it in start_kernel() so that call_single_queue can be initialized before enabling interrupts. The details of the crash are: (1) 2nd kernel boots up (2) A pending IPI from 1st kernel comes when irqs are first enabled in start_kernel(). (3) Kernel tries to handle the interrupt, but call_single_queue is not initialized yet at this point. As a result, in the generic_smp_call_function_single_interrupt(), NULL pointer dereference occurs when list_replace_init() tries to access &q->list.next. Therefore this patch changes the name of init_call_single_data() to call_function_init() and calls it before local_irq_enable() in start_kernel(). Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Milton Miller <miltonm@bga.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: kexec@lists.infradead.org Link: http://lkml.kernel.org/r/D6CBEE2F420741indou.takao@jp.fujitsu.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | gcov: disable CONFIG_CONSTRUCTORS when not needed by CONFIG_GCOV_KERNELJosh Triplett2011-06-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CONFIG_CONSTRUCTORS controls support for running constructor functions at kernel init time. According to commit b99b87f70c7785ab ("kernel: constructor support"), gcov (CONFIG_GCOV_KERNEL) needs this. However, CONFIG_CONSTRUCTORS currently defaults to y, with no option to disable it, and CONFIG_GCOV_KERNEL depends on it. Instead, default it to n and have CONFIG_GCOV_KERNEL select it, so that the normal case of CONFIG_GCOV_KERNEL=n will result in CONFIG_CONSTRUCTORS=n. Observed in the short list of =y values in a minimal kernel configuration. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Acked-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | init/calibrate.c: remove annoying printkBorislav Petkov2011-06-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove calibrate_delay_direct()'s KERN_DEBUG printk related to bogomips calculation as it appears when booting every core on setups with 'ignore_loglevel' which dmesg people scan for possible issues. As the message doesn't show very useful information to the widest audience of kernel boot message gazers, it should be removed. Introduced by commit d2b463135f84 ("init/calibrate.c: fix for critical bogoMIPS intermittent calculation failure"). Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Cc: Andrew Worsley <amworsley@gmail.com> Cc: Phil Carmody <ext-phil.2.carmody@nokia.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | uts: make default hostname configurable, rather than always using "(none)"Josh Triplett2011-06-15
|/ | | | | | | | | | | | | | | | | | | | | | | | | | The "hostname" tool falls back to setting the hostname to "localhost" if /etc/hostname does not exist. Distribution init scripts have the same fallback. However, if userspace never calls sethostname, such as when booting with init=/bin/sh, or otherwise booting a minimal system without the usual init scripts, the default hostname of "(none)" remains, unhelpfully appearing in various places such as prompts ("root@(none):~#") and logs. Furthermore, "(none)" doesn't typically resolve to anything useful. Make the default hostname configurable. This removes the need for the standard fallback, provides a useful default for systems that never call sethostname, and makes minimal systems that much more useful with less configuration. Distributions could choose to use "localhost" here to avoid the fallback, while embedded systems may wish to use a specific target hostname. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: David Miller <davem@davemloft.net> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Kel Modderman <kel@otaku42.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: Fix boot crash in mm_alloc()Linus Torvalds2011-05-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Thomas Gleixner reports that we now have a boot crash triggered by CONFIG_CPUMASK_OFFSTACK=y: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<c11ae035>] find_next_bit+0x55/0xb0 Call Trace: [<c11addda>] cpumask_any_but+0x2a/0x70 [<c102396b>] flush_tlb_mm+0x2b/0x80 [<c1022705>] pud_populate+0x35/0x50 [<c10227ba>] pgd_alloc+0x9a/0xf0 [<c103a3fc>] mm_init+0xec/0x120 [<c103a7a3>] mm_alloc+0x53/0xd0 which was introduced by commit de03c72cfce5 ("mm: convert mm->cpu_vm_cpumask into cpumask_var_t"), and is due to wrong ordering of mm_init() vs mm_init_cpumask Thomas wrote a patch to just fix the ordering of initialization, but I hate the new double allocation in the fork path, so I ended up instead doing some more radical surgery to clean it all up. Reported-by: Thomas Gleixner <tglx@linutronix.de> Reported-by: Ingo Molnar <mingo@elte.hu> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup: remove the ns_cgroupDaniel Lezcano2011-05-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ns_cgroup is an annoying cgroup at the namespace / cgroup frontier and leads to some problems: * cgroup creation is out-of-control * cgroup name can conflict when pids are looping * it is not possible to have a single process handling a lot of namespaces without falling in a exponential creation time * we may want to create a namespace without creating a cgroup The ns_cgroup was replaced by a compatibility flag 'clone_children', where a newly created cgroup will copy the parent cgroup values. The userspace has to manually create a cgroup and add a task to the 'tasks' file. This patch removes the ns_cgroup as suggested in the following thread: https://lists.linux-foundation.org/pipermail/containers/2009-June/018616.html The 'cgroup_clone' function is removed because it is no longer used. This is a userspace-visible change. Commit 45531757b45c ("cgroup: notify ns_cgroup deprecated") (merged into 2.6.27) caused the kernel to emit a printk warning users that the feature is planned for removal. Since that time we have heard from XXX users who were affected by this. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Jamal Hadi Salim <hadi@cyberus.ca> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Acked-by: Matt Helsley <matthltc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* printk: allocate kernel log buffer earlierMike Travis2011-05-25
| | | | | | | | | | | | | | | | | | | | On larger systems, because of the numerous ACPI, Bootmem and EFI messages, the static log buffer overflows before the larger one specified by the log_buf_len param is allocated. Minimize the overflow by allocating the new log buffer as soon as possible. On kernels without memblock, a later call to setup_log_buf from kernel/init.c is the fallback. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix CONFIG_PRINTK=n build] Signed-off-by: Mike Travis <travis@sgi.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Jack Steiner <steiner@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* init/calibrate.c: fix for critical bogoMIPS intermittent calculation failureAndrew Worsley2011-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A fix to the TSC (Time Stamp Counter) based bogoMIPS calculation used on secondary CPUs which has two faults: 1: Not handling wrapping of the lower 32 bits of the TSC counter on 32bit kernel - perhaps TSC is not reset by a warm reset? 2: TSC and Jiffies are no incrementing together properly. Either jiffies increment too quickly or Time Stamp Counter isn't incremented in during an SMI but the real time clock is and jiffies are incremented. Case 1 can result in a factor of 16 too large a value which makes udelay() values too small and can cause mysterious driver errors. Case 2 appears to give smaller 10-15% errors after averaging but enough to cause occasional failures on my own board I have tested this code on my own branch and attach patch suitable for current kernel code. See below for examples of the failures and how the fix handles these situations now. I reported this issue earlier here: Intermittent problem with BogoMIPs calculation on Intel AP CPUs - http://marc.info/?l=linux-kernel&m=129947246316875&w=4 I suspect this issue has been seen by others but as it is intermittent and bogoMIPS for secondary CPUs are no longer printed out it might have been difficult to identify this as the cause. Perhaps these unresolved issues, although quite old, might be relevant as possibly this fault has been around for a while. In particular Case 1 may only be relevant to 32bit kernels on newer HW (most people run 64bit kernels?). Case 2 is less dramatic since the earlier fix in this area and also intermittent. Re: bogomips discrepancy on Intel Core2 Quad CPU - http://marc.info/?l=linux-kernel&m=118929277524298&w=4 slow system and bogus bogomips - http://marc.info/?l=linux-kernel&m=116791286716107&w=4 Re: Re: [RFC-PATCH] clocksource: update lpj if clocksource has - http://marc.info/?l=linux-kernel&m=128952775819467&w=4 This issue is masked a little by commit feae3203d711db0a ("timers, init: Limit the number of per cpu calibration bootup messages") which only prints out the first bogoMIPS value making it much harder to notice other values differing. Perhaps it should be changed to only suppress them when they are similar values? Here are some outputs showing faults occurring and the new code handling them properly. See my earlier message for examples of the original failure. Case 1: A Time Stamp Counter wrap: ... Calibrating delay loop (skipped), value calculated using timer frequency.. 6332.70 BogoMIPS (lpj=31663540) .... calibrate_delay_direct() timer_rate_max=31666493 timer_rate_min=31666151 pre_start=4170369255 pre_end=4202035539 calibrate_delay_direct() timer_rate_max=2425955274 timer_rate_min=2425954941 pre_start=4265368533 pre_end=2396356387 calibrate_delay_direct() ignoring timer_rate as we had a TSC wrap around start=4265368581 >=post_end=2396356511 calibrate_delay_direct() timer_rate_max=31666274 timer_rate_min=31665942 pre_start=2440373374 pre_end=2472039515 calibrate_delay_direct() timer_rate_max=31666492 timer_rate_min=31666160 pre_start=2535372139 pre_end=2567038422 calibrate_delay_direct() timer_rate_max=31666455 timer_rate_min=31666207 pre_start=2630371084 pre_end=2662037415 Calibrating delay using timer specific routine.. 6333.28 BogoMIPS (lpj=31666428) Total of 2 processors activated (12665.99 BogoMIPS). .... Case 2: Some thing (presumably the SMM interrupt?) causing the very low increase in TSC counter for the DELAY_CALIBRATION_TICKS increase in jiffies ... Calibrating delay loop (skipped), value calculated using timer frequency.. 6333.25 BogoMIPS (lpj=31666270) ... calibrate_delay_direct() timer_rate_max=31666483 timer_rate_min=31666074 pre_start=4199536526 pre_end=4231202809 calibrate_delay_direct() timer_rate_max=864348 timer_rate_min=864016 pre_start=2405343672 pre_end=2406207897 calibrate_delay_direct() timer_rate_max=31666483 timer_rate_min=31666179 pre_start=2469540464 pre_end=2501206823 calibrate_delay_direct() timer_rate_max=31666511 timer_rate_min=31666122 pre_start=2564539400 pre_end=2596205712 calibrate_delay_direct() timer_rate_max=31666084 timer_rate_min=31665685 pre_start=2659538782 pre_end=2691204657 calibrate_delay_direct() dropping min bogoMips estimate 1 = 864348 Calibrating delay using timer specific routine.. 6333.27 BogoMIPS (lpj=31666390) Total of 2 processors activated (12666.53 BogoMIPS). ... After 70 boots I saw 2 variations <1% slip through [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix straggly printk mess] Signed-off-by: Andrew Worsley <amworsley@gmail.com> Reviewed-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: convert mm->cpu_vm_cpumask into cpumask_var_tKOSAKI Motohiro2011-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | cpumask_t is very big struct and cpu_vm_mask is placed wrong position. It might lead to reduce cache hit ratio. This patch has two change. 1) Move the place of cpumask into last of mm_struct. Because usually cpumask is accessed only front bits when the system has cpu-hotplug capability 2) Convert cpu_vm_mask into cpumask_var_t. It may help to reduce memory footprint if cpumask_size() will use nr_cpumask_bits properly in future. In addition, this patch change the name of cpu_vm_mask with cpu_vm_mask_var. It may help to detect out of tree cpu_vm_mask users. This patch has no functional change. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: David Howells <dhowells@redhat.com> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Hugh Dickins <hughd@google.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'kbuild' of ↵Linus Torvalds2011-05-24
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6: kbuild: make KBUILD_NOCMDDEP=1 handle empty built-in.o scripts/kallsyms.c: fix potential segfault scripts/gen_initramfs_list.sh: Convert to a /bin/sh script kbuild: Fix GNU make v3.80 compatibility kbuild: Fix passing -Wno-* options to gcc 4.4+ kbuild: move scripts/basic/docproc.c to scripts/docproc.c kbuild: Fix Makefile.asm-generic for um kbuild: Allow to combine multiple W= levels kbuild: Disable -Wunused-but-set-variable for gcc 4.6.0 Fix handling of backlash character in LINUX_COMPILE_BY name kbuild: asm-generic support kbuild: implement several W= levels kbuild: Fix build with binutils <= 2.19 initramfs: Use KBUILD_BUILD_TIMESTAMP for generated entries kbuild: Allow to override LINUX_COMPILE_BY and LINUX_COMPILE_HOST macros kbuild: Drop unused LINUX_COMPILE_TIME and LINUX_COMPILE_DOMAIN macros kbuild: Use the deterministic mode of ar kbuild: Call gzip with -n kbuild: move KALLSYMS_EXTRA_PASS from Kconfig to Makefile Kconfig: improve KALLSYMS_ALL documentation Fix up trivial conflict in Makefile
| * kbuild: move KALLSYMS_EXTRA_PASS from Kconfig to MakefileArtem Bityutskiy2011-04-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At the moment we have the CONFIG_KALLSYMS_EXTRA_PASS Kconfig switch, which users can enable or disable while configuring the kernel. This option is then used by 'make' to determine whether an extra kallsyms pass is needed or not. However, this approach is not nice and confusing, and this patch moves CONFIG_KALLSYMS_EXTRA_PASS from Kconfig to Makefile instead. The rationale is below. 1. CONFIG_KALLSYMS_EXTRA_PASS is really about the build time, not run-time. There is no real need for it to be in Kconfig. It is just an additional work-around which should be used only in rare cases, when someone breaks kallsyms, so Kbuild/Makefile is much better place for this option. 2. Grepping CONFIG_KALLSYMS_EXTRA_PASS shows that many defconfigs have it enabled, probably not because they try to work-around a kallsyms bug, but just because the Kconfig help text is confusing and does not really make it clear that this option should not be used unless except when kallsyms is broken. 3. And since many people have CONFIG_KALLSYMS_EXTRA_PASS enabled in their Kconfig, we do might fail to notice kallsyms bugs in time. E.g., many testers use "make allyesconfig" to test builds, which will enable CONFIG_KALLSYMS_EXTRA_PASS and kallsyms breakage will not be noticed. To address that, this patch: 1. Kills CONFIG_KALLSYMS_EXTRA_PASS 2. Changes Makefile so that people can use "make KALLSYMS_EXTRA_PASS=1" to enable the extra pass if needed. Additionally, they may define KALLSYMS_EXTRA_PASS as an environment variable. 3. By default KALLSYMS_EXTRA_PASS is disabled and if kallsyms has issues, "make" should print a warning and suggest using KALLSYMS_EXTRA_PASS Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> [mmarek: Removed make help text, is not necessary] Signed-off-by: Michal Marek <mmarek@suse.cz>
| * Kconfig: improve KALLSYMS_ALL documentationArtem Bityutskiy2011-04-15
| | | | | | | | | | | | | | | | | | | | Dumb users like myself are not able to grasp from the existing KALLSYMS_ALL documentation that this option is not what they need. Improve the help message and make it clearer that KALLSYMS is enough in the majority of use cases, and KALLSYMS_ALL should really be used very rarely. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next-2.6Linus Torvalds2011-05-23
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next-2.6: (28 commits) sparc32: fix build, fix missing cpu_relax declaration SCHED_TTWU_QUEUE is not longer needed since sparc32 now implements IPI sparc32,leon: Remove unnecessary page_address calls in LEON DMA API. sparc: convert old cpumask API into new one sparc32, sun4d: Implemented SMP IPIs support for SUN4D machines sparc32, sun4m: Implemented SMP IPIs support for SUN4M machines sparc32,leon: Implemented SMP IPIs for LEON CPU sparc32: implement SMP IPIs using the generic functions sparc32,leon: SMP power down implementation sparc32,leon: added some SMP comments sparc: add {read,write}*_be routines sparc32,leon: don't rely on bootloader to mask IRQs sparc32,leon: operate on boot-cpu IRQ controller registers sparc32: always define boot_cpu_id sparc32: removed unused code, implemented by generic code sparc32: avoid build warning at mm/percpu.c:1647 sparc32: always register a PROM based early console sparc32: probe for cpu info only during startup sparc: consolidate show_cpuinfo in cpu.c sparc32,leon: implement genirq CPU affinity ...
| * | SCHED_TTWU_QUEUE is not longer needed since sparc32 now implements IPIDaniel Hellstrom2011-05-20
| | | | | | | | | | | | | | | | | | | | | Signed-off-by: Daniel Hellstrom <daniel@gaisler.com> Reported-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | | Give up on pushing CC_OPTIMIZE_FOR_SIZELinus Torvalds2011-05-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I still happen to believe that I$ miss costs are a major thing, but sadly, -Os doesn't seem to be the solution. With or without it, gcc will miss some obvious code size improvements, and with it enabled gcc will sometimes make choices that aren't good even with high I$ miss ratios. For example, with -Os, gcc on x86 will turn a 20-byte constant memcpy into a "rep movsl". While I sincerely hope that x86 CPU's will some day do a good job at that, they certainly don't do it yet, and the cost is higher than a L1 I$ miss would be. Some day I hope we can re-enable this. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds2011-05-19
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (78 commits) Revert "rcu: Decrease memory-barrier usage based on semi-formal proof" net,rcu: convert call_rcu(prl_entry_destroy_rcu) to kfree batman,rcu: convert call_rcu(softif_neigh_free_rcu) to kfree_rcu batman,rcu: convert call_rcu(neigh_node_free_rcu) to kfree() batman,rcu: convert call_rcu(gw_node_free_rcu) to kfree_rcu net,rcu: convert call_rcu(kfree_tid_tx) to kfree_rcu() net,rcu: convert call_rcu(xt_osf_finger_free_rcu) to kfree_rcu() net/mac80211,rcu: convert call_rcu(work_free_rcu) to kfree_rcu() net,rcu: convert call_rcu(wq_free_rcu) to kfree_rcu() net,rcu: convert call_rcu(phonet_device_rcu_free) to kfree_rcu() perf,rcu: convert call_rcu(swevent_hlist_release_rcu) to kfree_rcu() perf,rcu: convert call_rcu(free_ctx) to kfree_rcu() net,rcu: convert call_rcu(__nf_ct_ext_free_rcu) to kfree_rcu() net,rcu: convert call_rcu(net_generic_release) to kfree_rcu() net,rcu: convert call_rcu(netlbl_unlhsh_free_addr6) to kfree_rcu() net,rcu: convert call_rcu(netlbl_unlhsh_free_addr4) to kfree_rcu() security,rcu: convert call_rcu(sel_netif_free) to kfree_rcu() net,rcu: convert call_rcu(xps_dev_maps_release) to kfree_rcu() net,rcu: convert call_rcu(xps_map_release) to kfree_rcu() net,rcu: convert call_rcu(rps_map_release) to kfree_rcu() ...
| * | | rcu: priority boosting for TREE_PREEMPT_RCUPaul E. McKenney2011-05-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add priority boosting for TREE_PREEMPT_RCU, similar to that for TINY_PREEMPT_RCU. This is enabled by the default-off RCU_BOOST kernel parameter. The priority to which to boost preempted RCU readers is controlled by the RCU_BOOST_PRIO kernel parameter (defaulting to real-time priority 1) and the time to wait before boosting the readers who are blocking a given grace period is controlled by the RCU_BOOST_DELAY kernel parameter (defaulting to 500 milliseconds). Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
| | | |
| \ \ \
*-. \ \ \ Merge branches 'sched-core-for-linus' and 'sched-urgent-for-linus' of ↵Linus Torvalds2011-05-19
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (60 commits) sched: Fix and optimise calculation of the weight-inverse sched: Avoid going ahead if ->cpus_allowed is not changed sched, rt: Update rq clock when unthrottling of an otherwise idle CPU sched: Remove unused parameters from sched_fork() and wake_up_new_task() sched: Shorten the construction of the span cpu mask of sched domain sched: Wrap the 'cfs_rq->nr_spread_over' field with CONFIG_SCHED_DEBUG sched: Remove unused 'this_best_prio arg' from balance_tasks() sched: Remove noop in alloc_rt_sched_group() sched: Get rid of lock_depth sched: Remove obsolete comment from scheduler_tick() sched: Fix sched_domain iterations vs. RCU sched: Next buddy hint on sleep and preempt path sched: Make set_*_buddy() work on non-task entities sched: Remove need_migrate_task() sched: Move the second half of ttwu() to the remote cpu sched: Restructure ttwu() some more sched: Rename ttwu_post_activation() to ttwu_do_wakeup() sched: Remove rq argument from ttwu_stat() sched: Remove rq->lock from the first half of ttwu() sched: Drop rq->lock from sched_exec() ... * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Fix rt_rq runtime leakage bug
| | * | | | slub: Revert "[PARISC] slub: fix panic with DISCONTIGMEM"David Rientjes2011-05-10
| | |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 4a5fa3590f09, which did not allow SLUB to be used on architectures that use DISCONTIGMEM without compiling NUMA support without CONFIG_BROKEN also set. The slub panic that it was intended to prevent is addressed by d9b41e0b54fd ("[PARISC] set memory ranges in N_NORMAL_MEMORY when onlined") on parisc so there is no further slub issues with such a configuration. The reverts allows SLUB now to be used on such architectures since there haven't been any reports of additional errors. Cc: James Bottomley <James.Bottomley@suse.de> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | / / Merge commit 'v2.6.39-rc7' into sched/coreIngo Molnar2011-05-12
| |\| | | | | |/ / | |/| |
| | * | Merge branch 'fixes' of ↵Linus Torvalds2011-04-27
| | |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jejb/parisc-2.6 * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/parisc-2.6: [PARISC] slub: fix panic with DISCONTIGMEM [PARISC] set memory ranges in N_NORMAL_MEMORY when onlined
| | | * | [PARISC] slub: fix panic with DISCONTIGMEMJames Bottomley2011-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Slub makes assumptions about page_to_nid() which are violated by DISCONTIGMEM and !NUMA. This violation results in a panic because page_to_nid() can be non-zero for pages in the discontiguous ranges and this leads to a null return by get_node(). The assertion by the maintainer is that DISCONTIGMEM should only be allowed when NUMA is also defined. However, at least six architectures: alpha, ia64, m32r, m68k, mips, parisc violate this. The panic is a regression against slab, so just mark slub broken in the problem configuration to prevent users reporting these panics. Cc: stable@kernel.org Acked-by: David Rientjes <rientjes@google.com> Acked-by: Pekka Enberg <penberg@kernel.org> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
| * | | | sched: Move the second half of ttwu() to the remote cpuPeter Zijlstra2011-04-14
| | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we've removed the rq->lock requirement from the first part of ttwu() and can compute placement without holding any rq->lock, ensure we execute the second half of ttwu() on the actual cpu we want the task to run on. This avoids having to take rq->lock and doing the task enqueue remotely, saving lots on cacheline transfers. As measured using: http://oss.oracle.com/~mason/sembench.c $ for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor ; do echo performance > $i; done $ echo 4096 32000 64 128 > /proc/sys/kernel/sem $ ./sembench -t 2048 -w 1900 -o 0 unpatched: run time 30 seconds 647278 worker burns per second patched: run time 30 seconds 816715 worker burns per second Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.515897185@chello.nl
* | | | kmemleak: Initialise kmemleak after debug_objects_mem_init()Catalin Marinas2011-05-19
| |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kmemleak frees objects via RCU and when CONFIG_DEBUG_OBJECTS_RCU_HEAD is enabled, the RCU callback triggers a call to free_object() in lib/debugobjects.c. Since kmemleak is initialised before debug objects initialisation, it may result in a kernel panic during booting. This patch moves the kmemleak_init() call after debug_objects_mem_init(). Reported-by: Marcin Slusarz <marcin.slusarz@gmail.com> Tested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: <stable@kernel.org>
* | | init/Kconfig: fix EXPERT menu listRandy Dunlap2011-04-26
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The EXPERT menu list was recently broken by the insertion of a kconfig symbol (EMBEDDED) at the beginning of the EXPERT list of kconfig items. Broken by: commit 6a108a14fa356ef607be308b68337939e56ea94e Author: David Rientjes <rientjes@google.com> Date: Thu Jan 20 14:44:16 2011 -0800 kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT Restore the EXPERT menu list -- don't inject a symbol (EMBEDDED) that does not depend on EXPERT into the list. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Peter Foley <pefoley2@verizon.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* / Fix common misspellingsLucas De Marchi2011-03-31
|/ | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* userns: add a user_namespace as creator/owner of uts_namespaceSerge E. Hallyn2011-03-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The expected course of development for user namespaces targeted capabilities is laid out at https://wiki.ubuntu.com/UserNamespace. Goals: - Make it safe for an unprivileged user to unshare namespaces. They will be privileged with respect to the new namespace, but this should only include resources which the unprivileged user already owns. - Provide separate limits and accounting for userids in different namespaces. Status: Currently (as of 2.6.38) you can clone with the CLONE_NEWUSER flag to get a new user namespace if you have the CAP_SYS_ADMIN, CAP_SETUID, and CAP_SETGID capabilities. What this gets you is a whole new set of userids, meaning that user 500 will have a different 'struct user' in your namespace than in other namespaces. So any accounting information stored in struct user will be unique to your namespace. However, throughout the kernel there are checks which - simply check for a capability. Since root in a child namespace has all capabilities, this means that a child namespace is not constrained. - simply compare uid1 == uid2. Since these are the integer uids, uid 500 in namespace 1 will be said to be equal to uid 500 in namespace 2. As a result, the lxc implementation at lxc.sf.net does not use user namespaces. This is actually helpful because it leaves us free to develop user namespaces in such a way that, for some time, user namespaces may be unuseful. Bugs aside, this patchset is supposed to not at all affect systems which are not actively using user namespaces, and only restrict what tasks in child user namespace can do. They begin to limit privilege to a user namespace, so that root in a container cannot kill or ptrace tasks in the parent user namespace, and can only get world access rights to files. Since all files currently belong to the initila user namespace, that means that child user namespaces can only get world access rights to *all* files. While this temporarily makes user namespaces bad for system containers, it starts to get useful for some sandboxing. I've run the 'runltplite.sh' with and without this patchset and found no difference. This patch: copy_process() handles CLONE_NEWUSER before the rest of the namespaces. So in the case of clone(CLONE_NEWUSER|CLONE_NEWUTS) the new uts namespace will have the new user namespace as its owner. That is what we want, since we want root in that new userns to be able to have privilege over it. Changelog: Feb 15: don't set uts_ns->user_ns if we didn't create a new uts_ns. Feb 23: Move extern init_user_ns declaration from init/version.c to utsname.h. Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Daniel Lezcano <daniel.lezcano@free.fr> Acked-by: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pid: remove the child_reaper special case in init/main.cEric W. Biederman2011-03-23
| | | | | | | | | | | | | | | | | | | | This patchset is a cleanup and a preparation to unshare the pid namespace. These prerequisites prepare for Eric's patchset to give a file descriptor to a namespace and join an existing namespace. This patch: It turns out that the existing assignment in copy_process of the child_reaper can handle the initial assignment of child_reaper we just need to generalize the test in kernel/fork.c Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Serge E. Hallyn <serge@hallyn.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* init: return proper error code in do_mounts_rd()Davidlohr Bueso2011-03-22
| | | | | | | | In do_mounts_rd() if memory cannot be allocated, return -ENOMEM. Signed-off-by: Davidlohr Bueso <dave@gnu.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* calibrate: retry with wider bounds when converge seems to failPhil Carmody2011-03-22
| | | | | | | | | | | | | | | | | | | | | | | | | | Systems with unmaskable interrupts such as SMIs may massively underestimate loops_per_jiffy, and fail to converge anywhere near the real value. A case seen on x86_64 was an initial estimate of 256<<12, which converged to 511<<12 where the real value should have been over 630<<12. This admitedly requires bypassing the TSC calibration (lpj_fine), and a failure to settle in the direct calibration too, but is physically possible. This failure does not depend on my previous calibration optimisation, but by luck is easy to fix with the optimisation in place with a trivial retry loop. In the context of the optimised converging method, as we can no longer trust the starting estimate, enlarge the search bounds exponentially so that the number of retries is logarithmically bounded. [akpm@linux-foundation.org: mention x86_64 SMIs in comment] Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* calibrate: home in on correct lpj value more quicklyPhil Carmody2011-03-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Binary chop with a jiffy-resync on each step to find an upper bound is slow, so just race in a tight-ish loop to find an underestimate. If done with lots of individual steps, sometimes several hundreds of iterations would be required, which would impose a significant overhead, and make the initial estimate very low. By taking slowly increasing steps there will be less overhead. E.g. an x86_64 2.67GHz could have fitted in 613 individual small delays, but in reality should have been able to fit in a single delay 644 times longer, so underestimated by 31 steps. To reach the equivalent of 644 small delays with the accelerating scheme now requires about 130 iterations, so has <1/4th of the overhead, and can therefore be expected to underestimate by only 7 steps. As now we have a better initial estimate we can binary chop over a smaller range. With the loop overhead in the initial estimate kept low, and the step sizes moderate, we won't have under-estimated by much, so chose as tight a range as we can. Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* calibrate: extract fall-back calculation into own helperPhil Carmody2011-03-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The motivation for this patch series is that currently our OMAP calibrates itself using the trial-and-error binary chop fallback that some other architectures no longer need to perform. This is a lengthy process, taking 0.2s in an environment where boot time is of great interest. Patch 2/4 has two optimisations. Firstly, it replaces the initial repeated- doubling to find the relevant power of 2 with a tight loop that just does as much as it can in a jiffy. Secondly, it doesn't binary chop over an entire power of 2 range, it choses a much smaller range based on how much it squeezed in, and failed to squeeze in, during the first stage. Both are significant optimisations, and bring our calibration down from 23 jiffies to 5, and, in the process, often arrive at a more accurate lpj value. The 'bands' and 'sub-logarithmic' growth may look over-engineered, but they only cost a small level of inaccuracy in the initial guess (for all architectures) in order to avoid the very large inaccuracies that appeared during testing (on x86_64 architectures, and presumably others with less metronomic operation). Note that due to the existence of the TSC and other timers, the x86_64 will not typically use this fallback routine, but I wanted to code defensively, able to cope with all kinds of processor behaviours and kernel command line options. Patch 3/4 is an additional trap for the nightmare scenario where the initial estimate is very inaccurate, possibly due to things like SMIs. It simply retries with a larger bound. Stephen said: I tried this patch set out on an MSM7630. : : Before: : : Calibrating delay loop... 681.57 BogoMIPS (lpj=3407872) : : After: : : Calibrating delay loop... 680.75 BogoMIPS (lpj=3403776) : : But the really good news is calibration time dropped from ~247ms to ~56ms. : Sadly we won't be able to benefit from this should my udelay patches make : it into ARM because we would be using calibrate_delay_direct() instead (at : least on machines who choose to). Can we somehow reapply the logic behind : this to calibrate_delay_direct()? That would be even better, but this is : definitely a boot time improvement. : : Or maybe we could just replace calibrate_delay_direct() with this fallback : calculation? If __delay() is a thin wrapper around read_current_timer() : it should work just as well (plus patch 3 makes it handle SMIs). I'll try : that out. This patch: ... so that it can be modified more clinically. This is almost entirely cosmetic. The only change to the operation is that the global variable is only set once after the estimation is completed, rather than taking on all the intermediate values. However, there are no readers of that variable, so this change is unimportant. Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* smp: move smp setup functions to kernel/smp.cAmerigo Wang2011-03-22
| | | | | | | | | | | | | | | | | Move setup_nr_cpu_ids(), smp_init() and some other SMP boot parameter setup functions from init/main.c to kenrel/smp.c, saves some #ifdef CONFIG_SMP. Signed-off-by: WANG Cong <amwang@redhat.com> Cc: Rakib Mullick <rakib.mullick@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Tejun Heo <tj@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: use appropriate printk priority levelsMandeep Singh Baines2011-03-22
| | | | | | | | | | | | | printk()s without a priority level default to KERN_WARNING. To reduce noise at KERN_WARNING, this patch set the priority level appriopriately for unleveled printks()s. This should be useful to folks that look at dmesg warnings closely. Signed-off-by: Mandeep Singh Baines <msb@chromium.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2011-03-18
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (47 commits) doc: CONFIG_UNEVICTABLE_LRU doesn't exist anymore Update cpuset info & webiste for cgroups dcdbas: force SMI to happen when expected arch/arm/Kconfig: remove one to many l's in the word. asm-generic/user.h: Fix spelling in comment drm: fix printk typo 'sracth' Remove one to many n's in a word Documentation/filesystems/romfs.txt: fixing link to genromfs drivers:scsi Change printk typo initate -> initiate serial, pch uart: Remove duplicate inclusion of linux/pci.h header fs/eventpoll.c: fix spelling mm: Fix out-of-date comments which refers non-existent functions drm: Fix printk typo 'failled' coh901318.c: Change initate to initiate. mbox-db5500.c Change initate to initiate. edac: correct i82975x error-info reported edac: correct i82975x mci initialisation edac: correct commented info fs: update comments to point correct document target: remove duplicate include of target/target_core_device.h from drivers/target/target_core_hba.c ... Trivial conflict in fs/eventpoll.c (spelling vs addition)
| * Merge branch 'master' into for-nextJiri Kosina2011-02-15
| |\
| * | Kconfig: BLK_THROTTLE -> BLK_DEV_THROTTLINGMichael Witten2011-01-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It would seem that `CONFIG_BLK_THROTTLE' doesn't exist, as it is only referenced in the documentation for `CONFIG_BLK_CGROUP'. The only other choice is `CONFIG_BLK_DEV_THROTTLING': $ git grep --cached THROTTL -- \*Kconfig block/Kconfig:config BLK_DEV_THROTTLING init/Kconfig: CONFIG_BLK_THROTTLE=y. Signed-off-by: Michael Witten <mfwitten@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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